我正在尝试为一种模型创建3种类型主机的家庭范围，该模型旨在根据三种主机类型的存在来模拟横向景观的移动。
使用上一篇文章中描述的一些代码，我创建了以下代码。当我运行模型时，我最终收到以下错误消息：
DISTANCE预期输入为代理，但却改为0。
非常感谢任何有关此问题的帮助。
以-去
if ((week-id = 13) or (week-id = 25) or (week-id = 33))
[ask patches
[sprout-mice 2
[set color gray
set shape "mouse side"
set size 0.5
setxy random-xcor random-ycor]
]
]
if week-id = 17[
let total-deer count deer
ask n-of (total-deer / 2) patches
[sprout-deer 1
[set color brown
set shape "deer"
set size 1
setxy random-xcor random-ycor]
]
]
if week-id = 17[
let total-raccoons count raccoons
ask n-of (total-raccoons) patches
[sprout-raccoons 1
[set color black
set shape "wolf 2"
set size 0.5
setxy random-xcor random-ycor]
]
]
mice-mortality
;print (count mice)
if (week-id = 40)
[deer-mortality]
;print(count deer)
if (week-id = 45)
[raccoon-mortality]
print (count raccoons)
ask deer
[deer-move]
ask raccoons
[raccoons-move]
ask mice
[mice-move]
子模型：
to deer-move
right random 50
left random 50
forward 1
end
to raccoons-move
ifelse distance home-patch > 10
[face home-patch]
[right random 90
left random 90]
forward 1
end
to mice-move
ifelse distance home-patch > 2
[face home-patch]
[right random 90
left random 90]
forward 1
end